// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MEDIA_CAST_CAST_ENVIRONMENT_H_
#define MEDIA_CAST_CAST_ENVIRONMENT_H_

#include <memory>

#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/single_thread_task_runner.h"
#include "base/time/tick_clock.h"
#include "base/time/time.h"
#include "media/cast/logging/log_event_dispatcher.h"

namespace media {
namespace cast {

    class CastEnvironment : public base::RefCountedThreadSafe<CastEnvironment> {
    public:
        // An enumeration of the cast threads.
        enum ThreadId {
            // The main thread is where the cast system is configured and where timers
            // and network IO is performed.
            MAIN,
            // The audio thread is where all send side audio processing is done,
            // primarily encoding / decoding but also re-sampling.
            AUDIO,
            // The video encoder thread is where the video processing is done.
            VIDEO,
        };

        CastEnvironment(
            std::unique_ptr<base::TickClock> clock,
            scoped_refptr<base::SingleThreadTaskRunner> main_thread_proxy,
            scoped_refptr<base::SingleThreadTaskRunner> audio_thread_proxy,
            scoped_refptr<base::SingleThreadTaskRunner> video_thread_proxy);

        // These are the same methods in message_loop.h, but are guaranteed to either
        // get posted to the MessageLoop if it's still alive, or be deleted otherwise.
        // They return true iff the thread existed and the task was posted.  Note that
        // even if the task is posted, there's no guarantee that it will run, since
        // the target thread may already have a Quit message in its queue.
        bool PostTask(ThreadId identifier,
            const tracked_objects::Location& from_here,
            const base::Closure& task);

        bool PostDelayedTask(ThreadId identifier,
            const tracked_objects::Location& from_here,
            const base::Closure& task,
            base::TimeDelta delay);

        bool CurrentlyOn(ThreadId identifier);

        // All of the media::cast implementation must use this TickClock.
        base::TickClock* Clock() const { return clock_.get(); }

        // Thread-safe log event dispatcher.
        LogEventDispatcher* logger() { return &logger_; }

        scoped_refptr<base::SingleThreadTaskRunner> GetTaskRunner(
            ThreadId identifier) const;

        bool HasAudioThread() { return audio_thread_proxy_.get() ? true : false; }

        bool HasVideoThread() { return video_thread_proxy_.get() ? true : false; }

    protected:
        virtual ~CastEnvironment();

        // Subclasses may final these.
        scoped_refptr<base::SingleThreadTaskRunner> main_thread_proxy_;
        scoped_refptr<base::SingleThreadTaskRunner> audio_thread_proxy_;
        scoped_refptr<base::SingleThreadTaskRunner> video_thread_proxy_;
        std::unique_ptr<base::TickClock> clock_;
        LogEventDispatcher logger_;

    private:
        friend class base::RefCountedThreadSafe<CastEnvironment>;

        DISALLOW_COPY_AND_ASSIGN(CastEnvironment);
    };

} // namespace cast
} // namespace media

#endif // MEDIA_CAST_CAST_ENVIRONMENT_H_
